Electronic components have become ubiquitous in modern society. The electronics industry proudly, but routinely, announces accelerated clocking speeds and smaller integrated circuit modules. While the benefits of these devices are myriad, smaller and faster electronic devices create problems. In particular, high clock speeds inherently require fast transitions between signal levels. Fast transitions between signal levels create electromagnetic emissions throughout the electromagnetic spectrum. Such emissions are regulated by the Federal Communications Commission (FCC) and other regulatory agencies. Furthermore, fast speed transitions inherently mean higher frequencies. Higher frequencies mean shorter wavelengths, requiring shorter conductive elements to act as antennas to broadcast these electromagnetic emissions. The electromagnetic emissions radiate from a source and may impinge upon other electronic components. If the signal strength of the emission at the impinged upon electronic component is high enough, the emission may interfere with the operation of the impinged upon electronic component. This phenomenon is sometimes called electromagnetic interference (EMI) or crosstalk. Dealing with EMI and crosstalk is sometimes referred to as electromagnetic compatibility (EMC). Other components, such as transceiver modules, inherently have many radiating elements that raise EMI concerns. Thus, even modules that do not have high clock speeds may need to address EMI issues. Furthermore, sub-modules making up a module may need to be shielded from EMI transmissions.
One way to reduce EMI to comply with FCC regulations is to shield the sub-modules. Typically the shield is formed from a grounded conductive material that surrounds the sub-module. When electromagnetic emissions from the sub-module strike the interior surface of the conductive material, the electromagnetic emissions are electrically shorted through the grounded conductive material, thereby reducing emissions. Likewise, when emissions from another radiating element strike the exterior surface of the conductive material, a similar electrical short occurs, and the sub-module does not experience EMI from other sub-modules.
However, as the sub-modules continue to become smaller from miniaturization, creating effective shields that do not materially add to the size of the sub-module becomes more difficult. Thus, there is a need for an electromagnetic shield that is inexpensive to manufacture on a large scale, does not substantially change the size of the sub-module, and effectively deals with EMI concerns.